Hall sensors are magnetic field sensors, which are based on the Hall effect and deliver an electrical output signal, which is proportional to a predetermined component of the magnetic field. A Hall sensor comprises a Hall element or a cluster of Hall elements and an electronic circuit for the operation of the Hall elements and the analysis of the output signals of the Hall elements. The Hall sensor is produced as an integrated circuit, which is embedded in a semiconductor chip. The semiconductor chip is packaged in a housing. Hall elements have an offset, which originates from deviations caused by processing and geometry. The offset can be effectively reduced by the parallel connection of multiple Hall elements (cluster) and/or operation using the known spinning current method. This is known from manifold patent documents, e.g. U.S. Pat. Nos. 6,768,301, 5,406,202, DE 4302342.
The semiconductor chip packaged in the housing is subjected to mechanical stress, which is dependent on environmental influences such as temperature and humidity, etc. The alternating mechanical stress causes changes of the offset of the Hall elements and, because of the piezo-Hall effect, also changes of the sensitivity of the Hall elements. Changes of the offset are effectively suppressed by the above-described measures. Employing a stress sensor, which detects the mechanical stress, and using its output signal to compensate for the change of the sensitivity of the Hall element caused by the piezo-Hall effect to compensate for the changes of the sensitivity is known, for example, from US 2005001487, DE 10154498, US 2005162160, US 2009108839.